Current wireless communication systems utilize several different radio communication standards and operate at many different frequency bands. In this fractured service environment, terminals operating in multiple systems and frequency bands offer a better service coverage. A multi-band antenna is a key component of a multi-band mobile terminal. It may also be used in a base station.
One example of a multi-band communication terminal is a mobile cellular telephone operable in any one of the four GSM system bands i.e. GSM850 (824-894 MHz), GSM900 (880-960 MHz), GSM1800 (1710-1880 MHz), GSM1900 (1850-1990 MHz). It is very challenging to design a compact internal antenna that operates at some or all of these frequency bands and has a good total efficiency.
In current mobile cellular telephones, various components such as a camera, a speaker or both have often been located at least partly between the internal antenna element and its ground plane. These additional components can degrade the antenna performance.
The user's hand, if brought close to the antenna, typically degrades the performance of the antenna at these frequency ranges. The effect is very strong when the hand is at least partly on top of the antenna. A user often holds a mobile cellular telephone so that a forefinger is on top of the antenna element near the top of the cellular telephone.
It would be desirable to provide an improved antenna.